Blank shell for guns



Jan. 3, 1967 w. GAHLE 3, ,4

BLANK SHELL FORGUNS Filed 001;. 23, 1964 United States Patent Ofiice 3,295,448 Patented Jan. 3, 1967 3,295,448 BLANK SHELL FOR GUNS Walter Gable, Unterluss-Hohenrieth, Germany, assignor to Firma Rheinmetall G.m.b.H., Dusseldorf, Germany Filed Oct. 23, 1964, Ser. No. 405,974 Claims priority, application Germany, Oct. 31, 1963,

36,459 1 Claim. Cl. 102-39 rated polyester resin with the addition of a hardening agent. This mixture is placed on a cover introduced into the cartridge case to seal-oil the charge of powder, the mixture then hardening into a tamping element and forming an air-tight seal over the charge.

It has now been found that this tamping element can also be employed with great advantage in a blank shell in which two or more tamping discs are arranged in the shell case at a distance from one another to form a compression chamber. By reason of the tamping material previously available and by virtue of the fact that the shell cases generally taper forwardly, only cut-down, i.e. shortened, live shell cases have heretofore been generally employed as blank shell cases to permit the introduction of the tamping discs and enable this to be eifected easily.

A tamping element consisting of a pasty mixture, however, also enables blank shells to be produced in a likewise economic manner from normal live shell cases and this has the advantage that the loading of the guns in practice or training firing is made more nearly to resemble battle conditions, since the dimensions of the blank ammunition correspond roughly to those of live ammunition.

According to the present invention the lower tamping element adjacent the propellent charge is formed within the shell case, while the upper tamping element is a prefabricated disc known per se which is pressed into the neck of the shell case.

It is extremely advantageous to fit a cardboard disc or the like on each side of the lower tamping element so that after formation of the tamping plug, i.e. after the tamping composition has been introduced, close contact of the mixture with the shell case wall is obtained and, so that after the mixture has hardened it adheres strongly to the wall.

Advantageously, a cavity is provided between the powder charge and the lower tamping element as a combustion chamber for the powder charge.

An example of embodiment of the invention is illustrated in the drawing which is a vertical cross-section of the embodiment.

Into the empty shell case 1, which is a normal live shell case, a cover 2, which may be a disc of cardboard or the like, is first introduced. A pasty mixture hardening into a rigid tamping element and consisting of filler and binder or adhesive supplied with a hardening agent is placed on this cover and slight pressure is applied thereto by means of another cover 4 which may also be a cardboard disc. During that operation, a pin may be introduced through a bore 5 to support the cover 2. The bore 5 is used subsequently to receive a threaded percussion primer. Owing to the pressure applied by means of the cover 4, the tamping composition is made to bear closely against the wall of the shell case, so that after hardening it is cemented tightly to the wall.

Known organic or inorganic materials can be employed as filler. It is advantageous to use ground cork in the form of cork powder or granulated cork. In particular, the comminution product known as carcass powder which is obtained from the side walls of motor vehicle tyres can be used as filler with very great advantage. The binder consists of a synthetic resin with the addition of a hardening agent. This mixture hardens at room temperature, being simultaneously cemented strongly to the wall of the shell case to form a tamping element. A prefabricated upper tamping element 6 which may be a disc or cup-shaped element of cardboard or the like is now pressed into the neck of the shell in known manner, a compression chamber 7 being formed between the upper tamping element 6 and the lower tamping element 3. The upper tamping element 6 is then advantageously painted with a varnish insulation 10 so that the chamber 7 is sealed to be air and moisture-tight.

The powder charge is then introduced through the bore 5 of the threaded percussion primer and the shell case is closed by screwing in a threaded percussion primer 8. A suitable blank-fire powder is chosen and the quantity of powder put in is advantageously so calculated that a cavity 9 is left between the powder charge and the adjacent lower tamping element 3. In this way a combustion chamber is created in which there can be built up a high gas pressure which, on the one hand, has a favourable influence on the acoustic effect and, on the other hand, also produces the complete destruction of the tamping element.

I claim:

A blank shell comprising in combination a shell case having an inwardly tapered upper end, a propellent charge located at one end of said case, a first tamping element located within said case adjacent said charge but spaced therefrom by a cavity, said first tamping element comprising a mixture of a filler and a hardenable binder, said mixture hardening after location within said case, a second tamping element located within the shell case in spaced relationship with said first tamping element, and a cover member on each side of the mixture to contain the latter introduced into the case as a paste-like mass.

References Cited by the Examiner UNITED STATES PATENTS 4/1903 Schutte 102-39 9/1963 Ormanns et 'al 10239 FOREIGN PATENTS 911,896 11/1962 Great Britain. 

